sstate.bbclass: Improve sstate_installpkg performance

In a pathological case, lots of files to process, the sstate_installpkg
performance was very poor.  It interated over each file and ran 3
individual sed commands per file.  Changing this to keep iterating
but running only a single command took about 1/3 time time.

However, when looking at the corresponding sstate_hardcode_path
function, it was clear we could optimize this further.

Using the same encoding logic to specify only the minimumal sed
operation necessary, and using xargs to avoid the os.system call the
install step was able to be performed in 13% of the original time.

Example timing numbers for perl:

3m7s original code
1m20s single sed, but interating
0m26s using xargs and limited sed

Signed-off-by: Mark Hatle <mark.hatle@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

0 files changed, 0 insertions, 0 deletions